Add custom parent classes as setup option.

README.rdoc

@@ -76,6 +76,18 @@ Make your model(s) that can follow other models acts_as_follower
     ...
   end
 
+Extended setup:
+  # config/initializers/acts_as_follower.rb
+
+  # By default list of parent classes includes only `[ApplicationRecord, ActiveRecord::Base]`.
+  ActsAsFollower.custom_parent_classes = [CustomRecord]
+
+  # OR
+
+  ActsAsFollower.setup do |c|
+    c.custom_parent_classes = [...]
+  end
+
 ---
 
 === acts_as_follower methods

lib/acts_as_follower.rb

@@ -6,5 +6,25 @@ module ActsAsFollower
   autoload :FollowerLib,  'acts_as_follower/follower_lib'
   autoload :FollowScopes, 'acts_as_follower/follow_scopes'
 
+  def self.setup
+    @configuration ||= Configuration.new
+    yield @configuration if block_given?
+  end
+
+  def self.method_missing(method_name, *args, &block)
+    @configuration.respond_to?(method_name) ?
+        @configuration.send(method_name, *args, &block) : super
+  end
+
+  class Configuration
+    attr_accessor :custom_parent_classes
+
+    def initialize
+      @custom_parent_classes = []
+    end
+  end
+
+  setup
+
   require 'acts_as_follower/railtie' if defined?(Rails) && Rails::VERSION::MAJOR >= 3
 end

lib/acts_as_follower/follower_lib.rb

@@ -3,12 +3,14 @@ module FollowerLib
 
     private
 
+    DEFAULT_PARENTS = [ApplicationRecord, ActiveRecord::Base]
+
     # Retrieves the parent class name if using STI.
     def parent_class_name(obj)
-      if obj.class.superclass != ActiveRecord::Base
+      unless parent_classes.include?(obj.class.superclass)
         return obj.class.superclass.name
       end
-      return obj.class.name
+      obj.class.name
     end
 
     def apply_options_to_scope(scope, options = {})
@@ -29,5 +31,11 @@ def apply_options_to_scope(scope, options = {})
       end
       scope
     end
+
+    def parent_classes
+      return DEFAULT_PARENTS unless ActsAsFollower.custom_parent_classes
+
+      ActsAsFollower.custom_parent_classes + DEFAULT_PARENTS
+    end
   end
 end

test/dummy30/app/models/application_record.rb

@@ -0,0 +1,3 @@
+class ApplicationRecord < ActiveRecord::Base
+  self.abstract_class = true
+end

test/dummy30/app/models/band.rb

@@ -1,4 +1,4 @@
-class Band < ActiveRecord::Base
+class Band < ApplicationRecord
   validates_presence_of :name
   acts_as_followable
 end

test/dummy30/app/models/custom_record.rb

@@ -0,0 +1,3 @@
+class CustomRecord < ActiveRecord::Base
+  self.abstract_class = true
+end

test/dummy30/app/models/some.rb

@@ -0,0 +1,5 @@
+class Some < CustomRecord
+  validates_presence_of :name
+  acts_as_follower
+  acts_as_followable
+end

test/dummy30/app/models/user.rb

@@ -1,4 +1,4 @@
-class User < ActiveRecord::Base
+class User < ApplicationRecord
   validates_presence_of :name
   acts_as_follower
   acts_as_followable

test/factories/somes.rb

@@ -0,0 +1,9 @@
+FactoryGirl.define do
+  factory :daddy, :class => Some do |b|
+    b.name 'Daddy'
+  end
+
+  factory :mommy, :class => Some do |b|
+    b.name 'Mommy'
+  end
+end

test/follow_test.rb

@@ -7,4 +7,55 @@ def test_assert_true_should_be_true
     assert true
   end
 
+  context "configuration with setters" do
+    should "contain custom parents" do
+      ActsAsFollower.custom_parent_classes = [CustomRecord]
+
+      assert_equal [CustomRecord], ActsAsFollower.custom_parent_classes
+    end
+  end
+
+  context "#setup" do
+    should "contain custom parents via setup" do
+      ActsAsFollower.setup do |c|
+        c.custom_parent_classes = [CustomRecord]
+      end
+
+      assert_equal [CustomRecord], ActsAsFollower.custom_parent_classes
+    end
+  end
+
+  context "with custom parents" do
+    setup do
+      @daddy = FactoryGirl.create(:daddy)
+      @mommy = FactoryGirl.create(:mommy)
+      @oasis = FactoryGirl.create(:oasis)
+      @metallica = FactoryGirl.create(:metallica)
+    end
+
+    should "be followed" do
+      ActsAsFollower.custom_parent_classes = [CustomRecord]
+
+      @daddy.follow(@mommy)
+      @daddy.follow(@metallica)
+      @mommy.follow(@oasis)
+      assert_equal true, @daddy.following?(@mommy)
+      assert_equal false, @mommy.following?(@daddy)
+      assert_equal true, @mommy.followed_by?(@daddy)
+      assert_equal false, @daddy.followed_by?(@mommy)
+      assert_equal true, @metallica.followed_by?(@daddy)
+      assert_equal true, @oasis.followed_by?(@mommy)
+      assert_equal true, @daddy.following?(@metallica)
+      assert_equal true, @mommy.following?(@oasis)
+    end
+
+    should "be not followed" do
+      ActsAsFollower.custom_parent_classes = []
+
+      @daddy.follow(@mommy)
+      @mommy.follow(@oasis)
+      assert_equal false, @daddy.following?(@mommy)
+      assert_equal false, @mommy.following?(@oasis)
+    end
+  end
 end

test/schema.rb

@@ -18,4 +18,8 @@
     t.column :name, :string
   end
 
+  create_table :somes, :force => true do |t|
+    t.column :name, :string
+  end
+
 end